Earth Radiation Budget, Top-of-Atmosphere Radiation

Synonyms

Extraterrestrial radiation; Longwave radiation; Shortwave radiation; Solar radiation; Terrestrial radiation; Thermal radiation

Definition

• 1. Extraterrestrial radiation: the radiative energy that radiates into the Earth’s climate system from the space.

• 2. Terrestrial radiation: the radiative energy emitted by the Earth’s climate system.

Introduction

The radiation at top of the atmosphere (TOA) is the only energy exchange process between the Earth and space for the Earth’s climate system. The incoming extraterrestrial radiation, dominantly from the sun, is the driving forcing for the general circulation of the climate system. In response to this solar radiative forcing, the climate system releases heat to the space through terrestrial thermal emission. For the Earth, the incoming solar radiation is generally balanced by the outgoing thermal radiation at TOA at the annual and longer timescales to maintain the climate system in a quasi-equilibrium state. Some anthropogenic...